The below discussion relates to the reprocessing (e.g., decontamination, disinfection, high-level disinfection, and/or sterilization) of endoscopes and other instruments that are used in medical procedures. In particular, the below discussion relates to an apparatus and a method that may be used to reprocess a medical device such as an endoscope after the medical device has been used in a first medical procedure, such that the medical device may be safely used in a subsequent medical procedure. While the below discussion will speak mainly in terms of an endoscope, it should be understood that the discussion may also equally apply to certain other medical devices.
An endoscope may have one or more working channels or lumens extending along at least a portion of the length of the endoscope. Such channels may be configured to provide a pathway for passage of other medical devices, etc., into an anatomical region within a patient. These channels may be difficult to clean and/or disinfect using certain primitive cleaning and/or disinfecting techniques. Thus, the endoscope may be placed in a reprocessing system that is particularly configured to clean endoscopes, including the channels within endoscopes. Such an endoscope reprocessing system may wash and disinfect the endoscope. Such an endoscope reprocessing system may include a basin that is configured to receive the endoscope, with a pump that flows cleaning fluids over the exterior of the endoscope within the basin. The system may also include ports that couple with the working channels of the endoscope and associated pumps that flow cleaning fluids through the working channels of the endoscope. The process executed by such a dedicated endoscope reprocessing system may include a detergent washing cycle, followed by a rinsing cycle, followed by a sterilization or disinfection cycle, followed by another rinsing cycle. The sterilization or disinfection cycle may employ disinfectant solution and water rinses. The process may optionally include an alcohol flush to aid displacement of water. A rinsing cycle may be followed by an air flush for drying and storage.
Examples of systems and methods that may be used to reprocess a used endoscope are described in U.S. Pat. No. 6,986,736, entitled “Automated Endoscope Reprocessor Connection with Integrity Testing,” issued Jan. 17, 2006, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,479,257, entitled “Automated Endoscope Reprocessor Solution Testing,” issued Jan. 20, 2009, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 7,686,761, entitled “Method of Detecting Proper Connection of an Endoscope to an Endoscope Reprocessor,” issued Mar. 30, 2010, the disclosure of which is incorporated by reference herein; and U.S. Pat. No. 8,246,909, entitled “Automated Endoscope Reprocessor Germicide Concentration Monitoring System and Method,” issued Aug. 21, 2012, the disclosure of which is incorporated by reference herein. An example of a commercially available endoscope reprocessing system is the EVOTECH® Endoscope Cleaner and Reprocessor (ECR) by Advanced Sterilization Products of Irvine, Calif.
For the disinfection cycle of a reprocessing system to be effective, it may be important to ensure that the disinfectant solution is sufficiently concentrated. Conventionally, disinfectant solutions may be sold as concentrated disinfectant stock solution, hereinafter, “concentrated stock solution.” While utilizing concentrated stock solution in an endoscope reprocessing system may provide for effective disinfection of an endoscope, the relatively high concentration of active ingredients in the concentrated stock solution may be unnecessarily harsh to, or incompatible with, various components of the endoscope. Thus, to decrease unnecessary wear and tear on an endoscope while still providing for a minimum effective concentration of disinfectant agent, an aliquot of concentrated stock solution may be diluted to an appropriate usage concentration before being employed in a disinfection cycle of an endoscope reprocessing system. Once the diluted disinfectant solution is used in a disinfection cycle, it may be discarded, and a new dose of concentrated stock solution diluted for use in a subsequent disinfection cycle.
Concentrated stock solution may be dosed out for usage in an endoscope reprocessing system over a protracted period of time, such as over the course of several hours, days, weeks, or even months. Consequently, disinfectant agent in the concentrated stock solution may become unstable and/or degrade, thereby reducing the potency of the concentrated stock solution. To compensate for the reduced potency, the known shelf-life of a disinfectant reagent may be utilized to estimate the concentration of disinfectant agent in a concentrated stock solution at any given time. Based upon the estimation, dilution of the concentrated stock solution may be decreased in an attempt to ensure that at least a minimum effective concentration of disinfectant agent is present in the disinfectant solution for use in a subsequent disinfection cycle.
Reliance upon assumptions of disinfectant agent concentration in a concentrated stock solution may result in a number of significant problems. For example, an endoscope to be disinfected may be inadvertently exposed to unnecessarily high concentrations of disinfectant agent, which may in turn shorten the useful life of the endoscope and/or components thereof. In addition, an errant assumption of disinfectant agent concentration may result in under-dilution of concentrated stock solution, which may in turn result in costly waste.
While a variety of systems and methods have been made and used to reprocess medical devices, it is believed that no one prior to the inventor(s) has made or used the technology as described herein.